Boiler-flue scraper



J. H. GOODFELLOW. V B0l-LER FLUE SCRAPER. APPLICATION FILED NOV. 22, 1920.

Patented Dec. 20

Similar characters of reference indicate corresponding parts. throughout the several views.

10 indicates the central shaft or spindle of the scraper which is preferably constructed of steel rod, being uniform diameter throughout its length, and having a suitable screw thread 11' at its rear end ex tending about one-third of its length. A stop 12, preferable consisting of a suitable collar is positioned near the front end of the shaft, as shown and held thereto by a. suitable pin 13.

Secured to the front end of the shaft is a suitable bell-shaped member 14; preferably of cast metal which may be secured thereto by a pin 15, the depth and diameter of the bell'portion 16 to be suiiicient for the requirements and proportion of the size of scrapers with which it is used. The ob ect of this bell-shaped member 1s to provlde a .circular housing, to regulate the possible diameter of expansion of the cutter arms, to provide a chamber in which the horns may freely vibrate between outer edge, and the shaft and to permit their escape as shown by dotted lines 2. The numeral 17 represents an open coil spring positioned on the said shaft in front of said stop, and of sufficient length to actuate the scraper saddle into normal position, A tube on sleeve 18, of suitable length and freely slidable and rotatable upon the said shaft, is provided with an external screw thread 19 with which a corresponding bore 29 of the saddle 21 engages. The forward end of this sleeve is provided with a plurality of radial slits or grooves 22, extending longitudinally of apart of its forward length, there being three equally spaced slits shown in the drawings, the office of these slits or grooves being to seat the spring resting therein, see 5-5, Figs. 2 and 5.

The numeral 23 represents a loose spacing tube adapted to engage the inside of the operating nut 24c having preferably an enlarged bell-shaped portion 25, and also an internal screw thread 26 for engagement with the thread 11 of the shaft 10. 27 is a jam nut to engage the rear of the bellshaped nut; 28 is an ordinary reducing connection, and 29 is a supplementary extension to the shaft 10, serving as a handle for the device.

The supporting saddle'21 which carries the cutters, as shown in this instance, is provided with three pairs of radial bifurcated lugs or cars 31, preferably of cast metal and integral with the saddle 2'1 and equally disposed thereon as shown in Figs. 4 and 5.

The, numeral 35 represents tie scraper blades or cutters each of which is of cast metal, preferably cast or malleable iron, and

preferably of. the form and contour or design shown in the drawlngs. Each of these arms is pivoted at 36 between a correspond ing set of lugs 31 on the saddle 21. Each blade is composed of two forwardly spreading V-shaped arms 37, 37, the forward ends being joined to the arched cutter head 38, which is shown beveled inward and rearwardly on its front face, see Figs. 1 and 3, while its rear wall 89 is correspondingly counter arched, and diametrically opposite their adjoining parts are wings kit) which are alternately offset so that each will overlap the adjoining cutter wing as shown in Figs. 1 and 1-,when the blades are fully compressed around the operating shaft, and thus aid in preventing any soot passing between them. 7

The forward end of each scraper blade is provided with a forwardly inclined horn 41 its forward end being adapted to engage the inside portion 16 of the bell-shaped member 1a The object of this horn is to depress the scraper blade and maintain any set diameter desired. Y

Arranged in the rear wall of the arched head 38 is an opening as. t?) represents a rectangular housing arranged at the apex of the bifurcated arms 87 just in front of the pivot 36, the side walls of which are fashioned to fit closely the width of the coil l9 of a-sprinp; 59, see 5, and the external outside walls have bosses 44:, through which a cotter pin 46 passes for supporting the spring in position therein. asshown.

The spring 50 is provided with an upper arched arm 48 which engage the hole 42 in the head 38 and a lower arm fil which is provided withan upturned end, the bow of which is adapted toengage with the corresponding slit 22 in the sleeve 18. Thus it will seen that, the said spring becomes double active whenever the scraper blades are moved in active position to have its horns within the bell-shaped member 14 and is also capable of removal or renewal by the adjustment of the cotter pin re.

"Whenit is desired to remove the scraper blades 35 the member. 25 is turned upon the shaft 10 until the coil spring 17 has pushed the sleeve 18 and blades back suiiicient to allow the horns to escape from the controlling bell-shaped member 14, as shown by dotted lines in Fig. 2, at which time any renewal or change can be made.

VJ hen these scraper blades are disengaged from the bell shaped member 14 they will swing wide open about their pivots'under the tension of the springs 50. By compressing them toward the shaft and by turning the rear bell 25 clockwise the sleeve 18' is moved forwardly together with the saddle 21 and blades 85, thereby compressing the spring 17' and storing up power for retraction when needed. As soon as the front ends of the horns 41 are within the forward lie pressed to any desired size. It is to be observed that no pressure on the front of the blades can affect any undue friction on the interior of the tube being acted upon, so

7 that the tremendous expansion 0 tained by this method. assures durability of the parts.

Another point of advantage is observed in the fact that the scraper, having been set to go through a tube at a diameter a little less than the actual diameter, goes through at that without any undue friction, yet, at the same time, as the scraper wears away the enlargement is made by turning the rear bell-shaped member to the left, and by setting the j am nut, will remain so.

By referring to Figs. 1 and 6, I have shown my improved method of doing two additional things; namely, grinding the scraper blades parallel and true, and at the same time preventing any cramping or wabbling of the rear end of the scraper in the tube, while going through, particularly of the single end type of scraper. I attain this result by extending the rear screw shaft, preferably by providing the disconnecting supplementary extension 29 on which is positioned a suitable sleeve 52 secured to said section by a pin 53 or any means that will locate it at a safe distance from the scraper.

This sleeve is provided with radial wings 54; having outer edges 55 preferably chilled as hard as possible and well rounded so that they may move through the soot with edgewise cleaving, and thus support the scraper rod centrally within the flue.

I claim as my invention:

1. A boiler flue scraper, comprising a shaft, a saddle slidable lengthwise on said shaft, scraper blades pivoted at one end to said saddle and capable of independent yieldable movement, the other ends of said blades being provided with forwardly tapering horns, a bell-shaped member mounted on said shaft in front of said saddle and cooperating with the horns of said blades for contracting; them upon the movement of said saddle toward said bell-shaped member, and means for permitting expansion of said blades when said saddle is moved in the opposite direction.

2. A boiler flue scraper comprising a shaft, a sleeve arranged on the latter and movable lengthwise thereon, saddle mounted on said sleeve, scraper blades pivoted to said saddle and capable of'expanding and contracting relatively to said shaft, controlling means fixed to said shaft and adapted to engage the free ends of said scraper blades, and means for imparting movement to said sleeve whereby said blades are moved toward and from said controlling means.

3. -A boiler flue scraper comprising a shaft, a sleeve arranged on the la ter and movable lengthwise thereon, a saddle mounted on said sleeve, scraper blades pivoted to said saddle andcapable of expanding and contracting relatively to said shaft, controlling means fixed to said shaft and adapted to engage the free ends of said scraper blades, means tending to resist contraction of said blades, and means f0 imparting movement to said sleeve whereby said blades are moved toward and from said controlling means.

i. A boiler flue scraper comprising a shaft, a sleeve arranged on the latter and movable lengthwise thereon, a saddle mounted on said sleeve, scraper blades pivoted to said saddle and capable of expanding and contracting relatively to said shaft, a bellshaped member cooperating with. the free ends of said blades, means connected with said shaf forimparting movement to said sleeve whereby said blades are moved toward said bell-shaped member, and means resisting the forward movement of said sleeve.

5. Aboiler flue scraper comprisingashaft, a saddle movable lengthwisethereoinscraper blades carried by said saddle and. capable of expanding and contracting relatively to said shaft, a bell-shaped member fixed to said shaft and adapted to engage the free ends of said scraper blades, means movable on said shaft for imparting movement to said saddlewhereby said blades are moved'toivard said bell-shaped member, and coil spring between said saddle and said bellshaped member for resisting such movement.

6. A boiler flue scraper comprising a shaft having a threaded portion, a saddle arranged on the latter and movable lengthwise thereon, scraper blades pivotally mounted. on, said saddle, a bell-shaped member fixed on said shaft and adapted to engage the free ends of said blades, a screw nut engaging the threaded portion of said shaft for moving said saddle toward said bell-shaped member, and a spring on said shaft tending to move said. ddle in the opposite direction.

7. A boiler flue scraper comprising a shaft having a threaded portion, a bell-shaped member secured at one end of the shaft, a saddle arranged on the latter and movable lengthwise thereon, scraperblades pivotally mounted on said saddle, the free ends of said blades tapering forwardly and adapted for engagement with. said bell-shaped member.'

an adjustable member engaging the threaded portion of said shaft for moving said saddle toward said bell-shaped member, means .arranged on said shaf" between. said saddle and said bell-shaped member for resisting the forward movement of said saddle, and means constantly tending to move said scraper blades outwardly relatively to said shaft. 7

8. A boiler flue scraper comprising a shaft, addle movable lengthwise thereon, scraper llades having forwardly spreading V-shaped arms pivotally mounted on said saddle, means on said shaft for contracting said blades when said saddle is moved in one direction, and a coil spring having forwardly extending legs carried by each 01" said blades, the coil of said spring being arranged between the rear connected ends of the arms of each blade and the legs thereof engaging said shaft and said blade respectively, whereby they are expanded when said saddle is moved in the opposite direction.

9. A boiler fine scraper comprising a shaft,

' a sleeve having radial slots rotatably mounted on said shaft and movable lengthwise thereon, a saddle mounted on said sleeve, scraper blades pivoted to said saddle and capable of expanding and contracting relatively to said shaft, a bell-shaped member cooperating with the free ends oi said blades, means connected with said shaft torimparting movement to said sleeve whereby said bladesare moved toward said bell-shaped member, means resisting the forward move 

